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Abstract: Between March 7 and April 12, 2008, several bay systems on the east (Gulf of Mexico) coast of Texas, USA were closed to the harvesting of oysters (Crassostrea virginica) due to the presence of the DSP (Diarrheic Shellfish Poisoning) toxin okadaic acid in excess of the 20 μg/100 g tissue FDA regulatory guidance level. This was the first shellfish harvesting closure due to the confirmed presence of DSP toxins in US history. Light microscopic cell counts were performed on water samples collected from numerous sampling sites along the Texas Gulf coast where shellfish harvesting occurs. Ultra performance liquid chromatography, electrospray ionization, selected reaction monitoring, mass spectrometry (UPLC/ESI/SRM/MS) was used to detect DSP toxins in oysters. The closures were associated with an extensive bloom of the dinoflagellate Dinophysis cf. ovum. Only okadaic acid (OA) and OA acyl esters were found in shellfish tissues (max. OA eq. levels 47 μg/100 g tissue). OA was also confirmed in a bloom water sample. No illnesses were reported associated with this event. DSP toxins now add to a growing list of phycotoxins, which include those responsible for PSP (paralytic shellfish poisoning), NSP (neurotoxic shellfish poisoning), and ASP (amnesic shellfish poisoning) which must now be monitored for in US coastal waters where shellfish are harvested. [Copyright &y& Elsevier]

The article describes some cases of ciguatera fish poisoning in Texas in 1998 and South Carolina in 2004. Ciguatera fish poisoning is characterized by nausea, vomiting and diarrhea, as well as weakness, tingling and pruritus. It is caused by eating fish that contain toxins produced by the dinoflagellate Gambierdiscus toxicus. In South Carolina, two cases of such poisoning involving a husband and wife were reported. The cases were associated with a barracuda they caught. In Texas, two cases were also reported where attendees of a dinner party were victimized. Snapper and barracuda fillets were served at the party.

Recalls how in 1997, the Southeast Texas Poison Center was contacted by a local physician requesting information about treatment of crew members of a cargo ship. Summary of an investigation of an outbreak by the Texas Department of Health which indicated that several crew members had experienced ciguatera fish poisoning resulting from eating a contaminated barracuda; Editorial note from the Centers for Disease Control and Prevention.

The article presents the study of ciguatera poisoning by the Department of State Health Services in Texas. It notes that ciguatera poisoning is a potential cause of gastrointestinal and neurological symptoms after eating predatory fish such as shark, barracuda, amberjack and red snapper. It also states that there is no antidote for ciguatera poisoning, the primary treatment is supportive care but Mannitol is used to treat its neurological symptoms.